1. Field of the Invention
The present invention relates to a computer having a resume function, i.e., a function of executing data processing, after the main power switch is turned back on, according to data processing state which had been in operation immediately before a main power switch was turned off.
2. Description of the Related Art
A computer having a resume function is known. The resume function is a function of resuming a job (data processing and/or display) which was in operation immediately before a main power switch was turned off when the main power switch is turned on.
The resume function is realized as follows. An ON/OFF (enable/disable) state of the resume function is set in a setup mode (installation mode). When the main power switch is turned off while the resume function is enabled, necessary data in memories, registers, and pointers are saved in a backup memory. When the main power switch is turned on again, the saved data are restored to their original locations. Thereafter, the job (data processing) continues according to the restored content.
In a conventional computer, when the resume function is enabled, even if a third party who has no right to use the computer turns on the main power switch of the computer, the contents of the data processing system immediately before the power switch was turned off is restored. For this reason, in a conventional computer having the resume function, the data saved by the resume function may be destroyed by a third party, thus posing a problem of data protection. Since a display in use when the power switch was turned off is displayed by the resume function when the power switch is turned on, the data may be presented to a third party.